POS0551 CLINICAL SIGNIFICANCE OF SERUM MPO-DNA COMPLEX IN RHEUMATOID ARTHRITIS
Authors: B. LI, J. Zhao, G. LI, Z. Zhang
Journal: Annals of the Rheumatic Diseases (2022)

Background Tumor necrosis factor inhibitors (TNFi) have been widely used in the treatment of RA. Few researches offered solid solution to predict the response of TNFi treatment. NETs formation (NETosis) is a key process participant in RA. NETs and their components also work as a source of auto-antigens for RA. Objectives To explore the relationship between serum MPO-DNA complex, which is one of the components of NETosis, and disease activity of RA, and to explore the possibility for serum MPO-DNA complex to predict the therapy response of anti-TNF therapy in RA patients. Methods RA patients were enrolled from a randomized controlled clinical trial (EScoRT study, ClinicalTrials.gov identifier: NCT02320630 ) conducted from Oct. 2014 to Oct. 2018. The clinical and demographic data and blood samples were collected at baseline and every 4 weeks. Serum levels of MPO-DNA complex were detected by a modified enzyme-linked immunosorbent assay (ELISA) kit. The Association between MPO-DNA complex level and disease activity was analyzed. The predictive value of baseline MPO-DNA complex for treatment response of RA patients was analyzed. Results 86 RA patients were enrolled. The level of serum MPO-DNA was higher in patients with high disease activity (HDA) than that in patients with medium disease activity (MDA) (1.10±0.32 vs. 0.86±0.29, p=0.001). After 4 weeks of treatments, the level of seurm MPO-DNA complex decreased significantly (1.0±0.3vs. 0.6±0.2, p&lt;0.001). Changes of MPO-DNA complex at week 4 (ΔMPO-DNA) was postively and linearly correlated with changes of TJC, SJC, PGA, EGA, ESR, CRP, DAS28ESR, DAS28CRP, SDAI and CDAI(r 0.270-0.495, all p-value&lt;0.05). Receiver operating characteristic (ROC) analysis revealed that baseline MPO-DNA complex (95% CIs 0.57-0.79 for ACR50 and 0.66-0.85 for ACR70, all p-value&lt;0.05) and ΔMPO-DNA complex at week 4 against baseline (95% CIs 0.63-0.83 for ACR 50 and 0.74-0.97 for ACR70) could predict the achievement of ACR50 and ACR70 within 12 weeks. ΔMPO-DNA complex at week 4 against baseline could predict the achievement of low disease activity (LDA) (95%CIs 0.57-0.79, p=0.03) and remission (95%CIs 0.54-0.8, p=0.024) within 12 weeks. Conclusion Serum MPO-DNA is associated with disease activity and can predict treatment response of RA.Serum MPO-DNA could serve as a powerful tool for clinicians to forecast the effectiveness of anti-TNF treatment in RA patients. Table 1. Predictive ability of MPO-DNA for treatment response at week 12 Measures AUCs for ACR50 at week 12 AUCs for ACR70 at week 12 AUC(95%CIs) P AUC difference p AUC(95%CIs) P AUC difference p b-MPO-DNA 0.68(0.57-0.79) 0.003 Reference - 0.77(0.66-0.85) &lt;0.001 Reference - b-ESR 0.48(0.36-0.61) 0.848 0.20 0.085 0.57(0.40-0.75) 0.332 0.20 0.036 b-CRP 0.55(0.43-0.68) 0.062 0.13 0.072 0.65(0.52-0.79) 0.044 0.12 0.135 ΔMPO-DNA 0.73(0.63-0.83) &lt;0.001 reference - 0.86(0.74-0.97) &lt;0.001 reference - ΔESR 0.56(0.48-0.68) 0.33 0.17 0.017 0.64(0.48-0.80) 0.072 0.22 0.007 ΔCRP 0.59(0.47-0.71) 0.14 0.14 0.056 0.68(0.53-0.83) 0.019 0.18 0.068 AUCs for DAS28ESR LDA at week 12 AUCs for DAS28ESR remission at week 12 Measures AUC(95%CIs) P AUC difference p AUC(95%CIs) P AUC difference p ΔMPO-DNA 0.68(0.57-0.79) 0.03 Reference - 0.67(0.54-0.8) 0.024 Reference - ΔESR 0.59(0.47-0.71) 0.14 0.09 0.226 0.54(0.41-0.68) 0.532 0.13 0.131 ΔCRP 0.60(0.47-0.72) 0.11 0.08 0.271 0.58(0.44-0.72) 0.274 0.08 0.258 Values are presented as areas under curve (95%CIs). Abbreviations: b-MPO-DNA/ESR/CRP, Serum MPO-DNA complex/ESR/CRP at baseline; ΔMPO-DNA/ESR/CRP, change of serum MPO-DNA/ESR/CRP at week 4 against baseline; ΔMPO-DNA/ESR/CRP%, reduction rate of serum MPO-DNA/ESR/CRP at week 4 against baseline. Disclosure of Interests None declared.